diff --git a/config/configuration.sample.yml b/config/configuration.sample.yml
index 5e90137357..bc00f45118 100644
--- a/config/configuration.sample.yml
+++ b/config/configuration.sample.yml
@@ -81,6 +81,7 @@ main:
             client_secret: null
 border-manager:
     enabled: true
+    extension-mapping: { }
     checkers:
         -
             type: Checker\Sha256
diff --git a/lib/Alchemy/Phrasea/Application.php b/lib/Alchemy/Phrasea/Application.php
index cf58d1a0cc..8de2f9c0e6 100644
--- a/lib/Alchemy/Phrasea/Application.php
+++ b/lib/Alchemy/Phrasea/Application.php
@@ -121,10 +121,6 @@ use Monolog\Logger;
 use Monolog\Processor\IntrospectionProcessor;
 use Neutron\Silex\Provider\ImagineServiceProvider;
 use MediaVorus\MediaVorusServiceProvider;
-use MediaVorus\Utils\RawImageMimeTypeGuesser;
-use MediaVorus\Utils\PostScriptMimeTypeGuesser;
-use MediaVorus\Utils\AudioMimeTypeGuesser;
-use MediaVorus\Utils\VideoMimeTypeGuesser;
 use MediaAlchemyst\MediaAlchemystServiceProvider;
 use Monolog\Handler\NullHandler;
 use MP4Box\MP4BoxServiceProvider;
@@ -151,8 +147,6 @@ use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
 use Symfony\Component\HttpKernel\KernelEvents;
 use Symfony\Component\HttpKernel\Event\GetResponseEvent;
-use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesser;
-use Symfony\Component\HttpFoundation\File\MimeType\FileBinaryMimeTypeGuesser;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\Routing\Generator\UrlGenerator;
 use Symfony\Component\Form\FormFactory;
@@ -476,14 +470,6 @@ class Application extends SilexApplication
         $this->mount('/permalink/', new Permalink());
         $this->mount('/lightbox/', new Lightbox());
 
-        $guesser = MimeTypeGuesser::getInstance();
-
-        $guesser->register(new FileBinaryMimeTypeGuesser());
-        $guesser->register(new RawImageMimeTypeGuesser());
-        $guesser->register(new PostScriptMimeTypeGuesser());
-        $guesser->register(new AudioMimeTypeGuesser());
-        $guesser->register(new VideoMimeTypeGuesser());
-
         $app['plugins.directory'] = $app->share(function () {
             $dir = __DIR__ . '/../../../plugins';
 
diff --git a/lib/Alchemy/Phrasea/Border/CustomExtensionGuesser.php b/lib/Alchemy/Phrasea/Border/CustomExtensionGuesser.php
new file mode 100644
index 0000000000..551e2cacf7
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Border/CustomExtensionGuesser.php
@@ -0,0 +1,36 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2014 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Alchemy\Phrasea\Border;
+
+use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface;
+
+class CustomExtensionGuesser implements MimeTypeGuesserInterface
+{
+    private $mapping;
+
+    public function __construct(array $mapping)
+    {
+        $this->mapping = $mapping;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function guess($path)
+    {
+        $extension = strtolower(pathinfo($path, PATHINFO_EXTENSION));
+
+        if (isset($this->mapping[$extension])) {
+            return $this->mapping[$extension];
+        }
+    }
+}
diff --git a/lib/Alchemy/Phrasea/Border/MimeGuesserConfiguration.php b/lib/Alchemy/Phrasea/Border/MimeGuesserConfiguration.php
new file mode 100644
index 0000000000..6129d281cc
--- /dev/null
+++ b/lib/Alchemy/Phrasea/Border/MimeGuesserConfiguration.php
@@ -0,0 +1,52 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2014 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Alchemy\Phrasea\Border;
+
+use Alchemy\Phrasea\Core\Configuration\Configuration;
+use MediaVorus\Utils\AudioMimeTypeGuesser;
+use MediaVorus\Utils\PostScriptMimeTypeGuesser;
+use MediaVorus\Utils\RawImageMimeTypeGuesser;
+use MediaVorus\Utils\VideoMimeTypeGuesser;
+use Symfony\Component\HttpFoundation\File\MimeType\FileBinaryMimeTypeGuesser;
+use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesser;
+
+class MimeGuesserConfiguration
+{
+    private $conf;
+
+    public function __construct(Configuration $conf)
+    {
+        $this->conf = $conf;
+    }
+
+    /**
+     * Registers mime type guessers given the configuration
+     */
+    public function register()
+    {
+        $guesser = MimeTypeGuesser::getInstance();
+
+        $guesser->register(new FileBinaryMimeTypeGuesser());
+        $guesser->register(new RawImageMimeTypeGuesser());
+        $guesser->register(new PostScriptMimeTypeGuesser());
+        $guesser->register(new AudioMimeTypeGuesser());
+        $guesser->register(new VideoMimeTypeGuesser());
+
+        if ($this->conf->isSetup()) {
+            $conf = $this->conf->getConfig();
+
+            if (isset($conf['border-manager']['extension-mapping']) && is_array($conf['border-manager']['extension-mapping'])) {
+                $guesser->register(new CustomExtensionGuesser($conf['border-manager']['extension-mapping']));
+            }
+        }
+    }
+}
diff --git a/lib/Alchemy/Phrasea/Core/Provider/BorderManagerServiceProvider.php b/lib/Alchemy/Phrasea/Core/Provider/BorderManagerServiceProvider.php
index 18c80f2255..b03507ae19 100644
--- a/lib/Alchemy/Phrasea/Core/Provider/BorderManagerServiceProvider.php
+++ b/lib/Alchemy/Phrasea/Core/Provider/BorderManagerServiceProvider.php
@@ -12,6 +12,7 @@
 namespace Alchemy\Phrasea\Core\Provider;
 
 use Alchemy\Phrasea\Border\Manager;
+use Alchemy\Phrasea\Border\MimeGuesserConfiguration;
 use Silex\Application;
 use Silex\ServiceProviderInterface;
 use XPDF\Exception\BinaryNotFoundException;
@@ -97,9 +98,14 @@ class BorderManagerServiceProvider implements ServiceProviderInterface
 
             return $borderManager;
         });
+
+        $app['border-manager.mime-guesser-configuration'] = $app->share(function (Application $app) {
+            return new MimeGuesserConfiguration($app['phraseanet.configuration']);
+        });
     }
 
     public function boot(Application $app)
     {
+        $app['border-manager.mime-guesser-configuration']->register();
     }
 }
diff --git a/lib/conf.d/configuration.yml b/lib/conf.d/configuration.yml
index 445451e7c0..481d633047 100644
--- a/lib/conf.d/configuration.yml
+++ b/lib/conf.d/configuration.yml
@@ -84,6 +84,7 @@ debugger:
     allowed-ips: []
 border-manager:
     enabled: true
+    extension-mapping: { }
     checkers:
         -
             type: Checker\Sha256
diff --git a/tests/Alchemy/Tests/Phrasea/Border/CustomExtensionGuesserTest.php b/tests/Alchemy/Tests/Phrasea/Border/CustomExtensionGuesserTest.php
new file mode 100644
index 0000000000..296d6bfaa6
--- /dev/null
+++ b/tests/Alchemy/Tests/Phrasea/Border/CustomExtensionGuesserTest.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace Alchemy\Tests\Phrasea\Border;
+
+use Alchemy\Phrasea\Border\CustomExtensionGuesser;
+
+class CustomExtensionGuesserTest extends \PhraseanetPHPUnitAbstract
+{
+    public function testGuess()
+    {
+        $conf = array(
+            'mpeg' => 'video/x-romain-neutron',
+        );
+
+        $guesser = new CustomExtensionGuesser($conf);
+        $this->assertNull($guesser->guess(__FILE__));
+        $this->assertEquals('video/x-romain-neutron', $guesser->guess('/path/to/video.mpeg'));
+    }
+}